Was the Risk from Nursing-Home Evacuation after the Fukushima Accident Higher than the Radiation Risk?

Michio Murakami; Kyoko Ono; Masaharu Tsubokura; Shuhei Nomura; Tomoyoshi Oikawa; Tosihiro Oka; Masahiro Kami; Taikan Oki

doi:10.1371/journal.pone.0137906

Was the Risk from Nursing-Home Evacuation after the Fukushima Accident Higher than the Radiation Risk?

PLoS One. 2015 Sep 11;10(9):e0137906. doi: 10.1371/journal.pone.0137906. eCollection 2015.

Authors

Michio Murakami¹, Kyoko Ono², Masaharu Tsubokura³, Shuhei Nomura⁴, Tomoyoshi Oikawa⁵, Tosihiro Oka⁶, Masahiro Kami³, Taikan Oki¹

Affiliations

¹ Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo, 153-8505, Japan.
² Research Institute of Science for Safety and Sustainability, National Institute of Advanced Industrial Science and Technology (AIST), 16-1, Onogawa, Tsukuba, 305-8569, Japan.
³ Division of Social Communication System for Advanced Clinical Research, The Institute of Medical Science, The University of Tokyo, 4-6-1, Shirokanedai, Minato, Tokyo, 108-8639, Japan.
⁴ Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, Norfolk Place, London W2 1PG, United Kingdom.
⁵ Department of Radiation Protection, Minamisoma Municipal General Hospital, 2-54-6 Takami, Haramachi, Minamisoma, Fukushima, 975-0033, Japan.
⁶ Faculty of Economics, Fukui Prefectural University, 4-1-1, Matsuoka-Kenjojima, Eiheiji-Town, Yoshida County, Fukui, 910-1195, Japan.

Abstract

After the 2011 accident at the Fukushima Daiichi nuclear power plant, nursing-home residents and staff were evacuated voluntarily from damaged areas to avoid radiation exposure. Unfortunately, the evacuation resulted in increased mortalities among nursing home residents. We assessed the risk trade-off between evacuation and radiation for 191 residents and 184 staff at three nursing homes by using the same detriment indicator, namely loss of life expectancy (LLE), under four scenarios, i.e. "rapid evacuation (in accordance with the actual situation; i.e. evacuation on 22 March)," "deliberate evacuation (i.e. evacuation on 20 June)," "20-mSv exposure," and "100-mSv exposure." The LLE from evacuation-related mortality among nursing home residents was assessed with survival probability data from nursing homes in the city of Minamisoma and the city of Soma. The LLE from radiation mortality was calculated from the estimated age-specific mortality rates from leukemia and all solid cancers based on the additional effective doses and the survival probabilities. The total LLE of residents due to evacuation-related risks in rapid evacuation was 11,000 persons-d-much higher than the total LLEs of residents and staff due to radiation in the other scenarios (27, 1100, and 5800 persons-d for deliberate evacuation, 20 mSv-exposure, and 100 mSv-exposure, respectively). The latitude for reducing evacuation risks among nursing home residents is surprisingly large. Evacuation regulation and planning should therefore be well balanced with the trade-offs against radiation risks. This is the first quantitative assessment of the risk trade-off between radiation exposure and evacuation after a nuclear power plant accident.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adult
Aged
Aged, 80 and over
Cause of Death
Female
Fukushima Nuclear Accident*
Humans
Male
Middle Aged
Mortality
Neoplasms / epidemiology
Neoplasms / etiology
Nursing Homes*
Radiation Exposure / adverse effects*
Rescue Work*
Risk

Grants and funding

This study was supported by a "Core Research for Evolutionary Science and Technology (CREST)" grant from the Japan Science and Technology Agency, http://www.jst.go.jp/kisoken/crest/en/index.html. MM and TOki receive the funding. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.